Two-way communications system



April 30, 1968 P. A. DURYEE TWO'WAY COMMUNICATIONS SYSTEM Filed Dec. 23, 1965 PHILIP A. DURYEE INVENTOR.

ATTORNE YS United States Patent 3,380,554 TWU-WAY QOMMUNICATEONS SYSTEM Philip A. Duryee, 1115 41st lE., Seattle, Wash. 98102 F iled Dec. 23, 1965, Ser. No. 541,865 4 Claims. (Cl. 182-46) The present invention relates to voice intercommunication systems, and particularly to those for voice communication between an elevated station and a ground system as, for example, on aerial platform vehicles utilized by electric utility companies for work on transmission lines and facilities.

Some such vehicles have been specially constructed to preclude grounding of the aerial platform via the elevating mechanism and vehicle frame. As disclosed, for example in United States Patent No. 3,087,581, this has been accomplished by constructing the platform of a dielectric material, introducing one or more boom sections of a dielectric material between the platform and the vehicle frame, and electrically insulating the control mechanism on the platform. The latter has been accomplished by use of control rods of dielectric material actuated from the platform such as shown in said patent, or by use of dielectric hydraulic lines to suitable control valves on the platform.

The foregoing accomplishments have not completely solved the safety problem for the aerial electrician in that, prior to the present invention, there has not been a satisfactory intercommunication system for voice transmission back and forth between the aerial platform and the vehicle cab. Radio intercommunication is subject to interference, particularly in the vicinity of power transmission lines, and in urban areas it is often ditiicult to find or maintain a clear channel. On the other hand the conventional intercom is objectionable because of the grounding danger created in the wiring to the speaker-microphone in the aerial platform.

Accordingly the present invention aims to provide an improved reliable electrically-safe intercommunication system for aerial platforms which will overcome the above difficulties and yet be of simple and economical construction and also easy to install.

Other objects and advantages in view will appear and be understood in the following description and claims, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIG. 1 is a side elevational view of an aerial platform vehicle equipped with an interco-mmunications system in accordance with the present invention;

FIG. 2 is an enlarged transverse sectional View taken along the line 22 of FIG. 1;

FIG. 3 is a fragmentary perspective view of the aerial platform and the outer end of the upper boom; and

FIG. 4 is a schematic of the intercom system.

Illustrated in the drawings is an aerial platform truck of the general type shown in Patent No. 3,087,581, as exemplary of a typical unit on which the present invention can be utilized. This truck 10 includes a frame 11 provided with ground-engaging wheel and axle assemblies 12, a forward cab 13, and a rear turntable 14. One or more outrigger units 15 are carried by the frame 11 on both sides of the vehicle for selective ground engagement to give added stability when required.

The turntable 14 is rotatable about a vertical axis and has a pair of upright supports 16 between which a lower boom 17 is swingably mounted about a horizontal pin axis 18 in response to an hydraulic cylinder assembly 20' seated on the turntable. An upper boom 21 is pivotally joined 'ice to the outer end of the lower boom for swinging movement about a second horizontal axis 19 spaced from the axis 18. A second hydraulic cylinder assembly 22 carried by the lower boom acts on the knee of a toggle 23 interconnecting the two booms to raise and lower the upper boo-m relative to the lower one.

At its outer end the upper boom carries an aerial platform which may take the form of a basket 24 which has a pair of ear extensions 25 receiving the tip of the boom for horizontal swinging movement relative thereto about a pin connection 26. In order to keep the basket 24 horizontal during lifting thereof, a suitable leveling mechanism is provided which may take the form of upper and lower rods 27-28 and an intermediate link which is pivotally mounted at the connection between the booms. The upper rod 27 is pivotally connected at its ends to the basket and the upper end of the link 30' while the lower rod 28 is pivotally connected to the lower end of the link 30 and the turntable supports 16 so that rods 27-28 are respectively maintained in parallel relation to the longitudinal axes of the upper and lower booms. This arrangement keeps the floor of the basket 24 parallel to the ground surface.

The upper boom 21 has a metal lower sleeve 31 with a lateral tongue extension 31a which is pivotally connected to the upper end of the lower boom, and has a tubular main section 32 fitting into the sleeve 31. This main section 32, the basket 24, and the upper rod 27 are each formed of a suitable dielectric material as disclosed in Patent No. 3,087,581, such for example as glass fiber-reinforced polyester resin.

It is desirable that the electrician or other worker on the aerial platform be able to control the platform in train and elevation by remote controls located at the platform. These controls can be by way of mechanical linkages which have dielectric parts from the platform through or along the dielectric section 32 of the upper boom as shown in Patent No. 3,087,581 or, as shown in the accompanying drawings, the controls may be via hydraulic lines or hoses 33 composed of rubber, glass fiberreinforced polyester resin, or some other suitable dielectric material. Preferably these lines 33 extend longitudinally through the booms from the respective power units and are flexible at least at the boom articulations.

Within the upper boom the lines 33 extend through baffles or cross-webs 3d of dielectric 'material which reinforce the boom section 32, and then flexibly loop out of the upper end of the upper boom into a control box 35 on the basket located, for example, between the extensions 25. Suitable control valves in this box have their control handles 36 in easy access to an operator within the basket.

The aforedescribed apparatus has been known in the art prior to the present invention, but has not had associated therewith a satisfactory intercom system between the aerial platform 24 and the cab 13. In accordance with the present invention, a horn 40 is conveniently mounted on the aerial platform, as for example, on the control box 35. Extending from the base of the horn is a tube 41 of dielectric material which may be gathered with the hydraulic lines 33 and like them has a flexible loop 41a between the upper boom 21 and the aerial platform to permit relative movement between the platform and boom. The tube 41 continues longitudinally through the main section 32 of the upper boom and may be supported by the crosswebs 34. Within the lower sleeve 31 of the upper boom the tube 41 is connected to the driver 42 for the born 40. By this arrangement the sound waves are transmitted by the dielectric tube 41 from the driver to the horn free of any electrical wiring or connection between the lower sleeve 31 and the aerial platform. It

desired, the tube 41 may be of a hard rigid dielectric material between the flexible loop 41a and the driver 42 to minimize any dampening effect.

The diver 42 may be conventionally connected in a two-way intercom circuit (FIG. 4) with a master control speaker/microphone 43 and a push-to-talk switch 44- conveniently located in the cab 13. The amplifier 45 and related system components and controls are also preferably housed in the cab 13, and the wiring therefrom to the driver 42 is strung from the cab through the lower boom 17 and related articulations up to the driver 42.

By this arrangement the horn 40 serves as a combination microphone/speaker for the worker on the aerial platform Without need by him of operation of any controls or switches. The vehicle operator in the cab can at all times instantly hear directions and emergency signals voiced by the aerial worker into the horn 4t), and may 7 talk back to the worker while holding in the switch 44.

Any conventional driver 42. may be used in the system including a cone speaker, the significant feature of the intercom in the present invention being the electrical isolation of the aerial platform horn from its driver by a dielectric tube.

It is thought that the invention will have been clearly understood from the foregoing detailed description. Changes in the details of construction will suggest themselves and may be resorted to without departing from the spirit of the invention, wherefore it is my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.

I claim:

1. In combination, a vehicle with a frame and a cab on the frame, a dielectric aerial platform, boom means carried by the frame for elevating and training said aerial platform, said means including an elongated dielectric section adjoining said platform, hydraulic means for moving said boom means, dielectric control means from said aerial platform to said hydraulic means, and a two-way intercommunications system between said aerial platform and cab including a horn on said platform, a driver on said boom means separated by said dielectric section from said aerial platform, and dielectric tube means passing along said dielectric section and operatively interconnecting said horn and driver.

2. In combination, a vehicle with a mobile frame, an aerial platform, support means on the frame for carrying and selectively moving the aerial platform in train and elevation relative to the frame and including dielectric means electrically isolating said aerial platform from the frame, an intercommunication system betwen said platform and vehicle frame having a master station on said frame separated from said support means and having a remote station with a horn on said aerial platform, a driver on said support means electrically insulated from said platform by said dielectric means and operatively connected to the master station, and dielectric tube means operatively interconnecting said horn and driver.

3. The combination according to claim 2 in which said aerial platform has a pivotal connection with said support means and in which said dielectric tube means has a flexible section adjoining said pivotal connection.

4. The combination according to claim 2 in which said intercommunication system includes a microphone/ speaker at the master station connected to the driver and controlled by a push-to-talk switch at the master station, said aerial platform being free of controls for said system.

References Cited UNITED STATES PATENTS 961,157 6/1910 Perry 18122 1,654,193 12/1927 Steuart ISL-22 3,136,385 6/1964 Eitel 1822 1,771,774 7/1930 COX 18122 REINALDDO P. MACHADO, Primary Examiner. 

1. IN COMBINATION, A VEHICLE WITH A FRAME AND A CAB ON THE FRAME, A DIELECTRIC AERIAL PLATFORM, BOOM MEANS CARRIED BY THE FRAME FOR ELEVATING AND TRAINING SAID AERIAL PLATFORM, SAID MEANS INCLUDING AN ELONGATED DIELECTRIC SECTION ADJOINING SAID PLATFORM, HYDRAULIC MEANS FOR MOVING SAID BOOM MEANS, DIELECTRIC CONTROL MEANS FROM SAID AERIAL PLATFORM TO SAID HYDRAULIC MEANS, AND A TWO-WAY INTERCOMMUNICATIONS SYSTEM BETWEEN SAID AERIAL PLATFORM AND CAB INCLUDING A HORN ON SAID PLATFORM, A DRIVER ON SAID BOOM MEANS SEPARATED BY SAID DIELECTRIC SECTION FROM SAID AERIAL PLATFORM, AND DIELECTRIC TUBE MEANS PASSING ALONG SAID DIELECTRIC SECTION AND OPERATIVELY INTERCONNECTING SAID HORN AND DRIVER. 